Quick Maths

TIME

Before starting the lesson, know the starting time and ending time.

Clock –> Clock helps us to know the time. The face or area of the clock is divided into twelve equal parts, marked with numbers 1 to 12. 

Most of the clocks have two hands. One hand is long and other hand is short. 

Hour Hand –> The short hand is the hour hand. It shows hours. The hour hand moves from one number (on the face of the clock) to the next in one hour.

It moves from 1 to 2, 2 to 3, 3 to 4, and so on to 12. So, it takes 12 hours to complete one full round of the clock.

1 Full Round = 12 Big divisions

Minute Hand –> The long hand is the minute hand. It shows minutes. 

We know that there are 12 big divisions marked 1 to 12 on the face of the clock. 

Each division is also divided into five small division, between any two big divisions. 

Each small division stands for 1 minute so there are (12×5) 60 small divisions.

1 Full Round = 60 small divisions

Therefore, 

1 hour =  60 minutes 

Second Hand –> Some clocks have third hand. It is the thinnest hand of the clock and known as second hand. 

The second hand takes 60 seconds or 1 minute to complete one round of the clock i.e., 

1 minute = 60 seconds 

One Day –> The time between one mid night to the next mid night is called one day. 

The hour hand takes 12 hours to complete 1 round. 

Since a day has 24 hours, the hour hand completes two rounds in a day or in 24 hours. i.e., 1 Day = 24 Hours

So, 1 Day = 24 x 60 = 1440 minutes 

    (1 hour =60 minutes) 

Minutes In An Hour And Hours In A Day

★ The minute hand takes 1 hour to go around the face of the clock once. So, there are 60 minutes in 1 hour. 

★ Hence, there are 2 x 60 minutes in 2 hours. So, there are 120 minutes in 2 hours. 

★ Similarly, there are 3 x 60 minutes in 3 hours. Hence, there are 180 minutes in 3 hours. 

★ The hour hand takes 12 hours to go around the clock once. In a day, the hour hand goes around the clock twice. So, there are 24 hours in a day.

Conversion of Time:

1 day = 24 hours

1 hour = 60 minutes

1 minute = 60 seconds

Remember

The earth takes one day to go around itself completely. This means the earth completes one rotation in 24 hours.

Q. 1: How many hours are there in 4 days?

Sol. We know that,

1 day = 24 hours

4 days = 4 x 24 hours

             = 96 hours.

There are 96 hours in 4 days.